/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.aop.support.annotation;

import java.lang.annotation.Annotation;
import java.lang.reflect.Method;

import org.springframework.aop.support.AopUtils;
import org.springframework.aop.support.StaticMethodMatcher;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;

/**
 * Simple MethodMatcher that looks for a specific Java 5 annotation
 * being present on a method (checking both the method on the invoked
 * interface, if any, and the corresponding method on the target class).
 *
 * @author Juergen Hoeller
 * @see AnnotationMatchingPointcut
 * @since 2.0
 */
public class AnnotationMethodMatcher extends StaticMethodMatcher {

    private final Class<? extends Annotation> annotationType;

    private final boolean checkInherited;


    /**
     * Create a new AnnotationClassFilter for the given annotation type.
     *
     * @param annotationType the annotation type to look for
     */
    public AnnotationMethodMatcher(Class<? extends Annotation> annotationType) {
        this(annotationType, false);
    }

    /**
     * Create a new AnnotationClassFilter for the given annotation type.
     *
     * @param annotationType the annotation type to look for
     * @param checkInherited whether to also check the superclasses and
     * interfaces as well as meta-annotations for the annotation type
     * (i.e. whether to use {@link AnnotationUtils#findAnnotation(Method, Class)}
     * semantics instead of standard Java {@link Method#isAnnotationPresent})
     * @since 5.0
     */
    public AnnotationMethodMatcher(Class<? extends Annotation> annotationType, boolean checkInherited) {
        Assert.notNull(annotationType, "Annotation type must not be null");
        this.annotationType = annotationType;
        this.checkInherited = checkInherited;
    }


    @Override
    public boolean matches(Method method, @Nullable Class<?> targetClass) {
        if (matchesMethod(method)) {
            return true;
        }
        // The method may be on an interface, so let's check on the target class as well.
        Method specificMethod = AopUtils.getMostSpecificMethod(method, targetClass);
        return (specificMethod != method && matchesMethod(specificMethod));
    }

    private boolean matchesMethod(Method method) {
        return (this.checkInherited ?
                (AnnotationUtils.findAnnotation(method, this.annotationType) != null) :
                method.isAnnotationPresent(this.annotationType));
    }

    @Override
    public boolean equals(Object other) {
        if (this == other) {
            return true;
        }
        if (!(other instanceof AnnotationMethodMatcher)) {
            return false;
        }
        AnnotationMethodMatcher otherMm = (AnnotationMethodMatcher) other;
        return this.annotationType.equals(otherMm.annotationType);
    }

    @Override
    public int hashCode() {
        return this.annotationType.hashCode();
    }

    @Override
    public String toString() {
        return getClass().getName() + ": " + this.annotationType;
    }

}
